As therapeutic corneoscleral cross-linking using riboflavin photochemistry continues to gain widespread clinical application, there exists ongoing interest in developing an alternative approach to such therapy that obviates the need for ultraviolet irradiation exposure and is delivered topically. In addition to nitroalcohols, several agents including glyceraldehyde and genipin have been proposed for such uses. The present study was undertaken in order to compare the cell toxicity of such agents.

The results are summarized in Table 1. Overall, the toxicity levels varied between cross-linking agents by a factor of 100x with the least toxic being NE, glyceraldehyde, and NP. MNPD, HNPD, polymeric PA, and polymeric GA showed intermediate toxicity. The most toxic agents were GP and BP. Toxicity levels were generally in agreement between cell types although in some cases there was as much as a 10x difference for a given compound when comparing between cell types.

Conclusions

Regarding cell toxicity, there are significant differences between topical cross-linking compounds. In addition, for a given compound, toxicity can vary by cell type. Such differences should be considered when selecting agents to use for topical therapeutic corneoscleral tissue cross-linking.